1. Field of the Invention
The present invention concerns a signal processing system for peak detection in an electrocardiogram (ECG) signal processing and analysis system, for example.
2. Description of the Related Art
An electrocardiogram (ECG) waveform or signal includes a series of characteristic points conventionally designated by the letters P, Q, R, S, and T. The Q, R, and S portions of the wave when taken together are referred to as a “QRS complex”. The R-wave of the QRS complex is the most prominent wave in each cardiac cycle of the ECG signal.
Therefore, an efficient automatic detection of time instants of R-peaks is important in various ECG signal processing applications, such as Heart Rate Variability (HRV) analysis, computer-aided cardiac diagnostic system, Fetal Heart Rate (FHR) monitor, heart sound detection, ECG-based biometric system, ECG compression system, cardiac event change detector, wireless medical body area network, remote cardiac patient monitoring system, and other ECG signal processing applications.
Different digital processing systems and methods implement methods for detecting R-peaks or QRS complexes. Such methods can include, for example, Digital Filter (DF), filter-banks, Geometrical Matching (GM), genetic algorithms, Hilbert Transform (HT), Higher-Order Statistics (HOS), Hidden Markov Model (HMM), Linear Prediction (LP), Maximum-a-Posteriori (MAP) estimation, matched filters, mathematical morphology, multi-scale mathematical morphology, 3M and Empirical Mode Decomposition (EMD), syntactical rules, neural networks, Support Vector Machine (SVM), Template Matching (TM), Two-pole recursive filter, Wavelet Transform (WT), Zero-Crossing (ZC), and various other methods.
Although the known methods described above are effective in detecting R-peaks in an ECG signal, the known methods may have compromised performance when processing wide QRS complexes, low-amplitude QRS complexes, negative QRS polarities, sudden changes in RR intervals, sudden changes in QRS amplitudes, sudden changes in QRS morphologies, sharp P/T waves, and various kinds of noise (or artifacts) including baseline wander, power-line interference, muscle artifacts, electrosurgical noise, and motion artifacts. A system according to invention principles addresses these deficiencies and related problems and provides a robust system for automatically determining time instants of R-peaks in a received or recorded signal.